1. Field of the Invention
The present invention relates to a monolithic ceramic capacitor. In particular, the present invention relates to a monolithic ceramic capacitor including a ceramic sintered body, and a plurality of first and second inner electrodes that are alternately arranged inside the ceramic sintered body so as to be opposed to each other with a ceramic layer interposed between the adjacent first and second inner electrodes.
2. Description of the Related Art
Previously, monolithic ceramic capacitors, for example, have been used in many electronic devices, such as cellular phones and notebook personal computers.
With a recent trend toward smaller sizes and higher performance of electronic devices in which monolithic ceramic capacitors are mounted, monolithic ceramic capacitors having smaller sizes and higher capacities have been developed. As large-capacity capacitors of 10 μF to 100 μF, for example, an aluminum electrolytic capacitor and a tantalum capacitor have been primarily used to date. However, the use of monolithic ceramic capacitors has also begun.
Generally, the electrostatic capacity of a monolithic ceramic capacitor is proportional to the relative dielectric constant of a dielectric layer, the area in which inner electrodes are opposed to each other, and the number of stacked inner electrodes and is inversely proportional to the thickness of the dielectric layer. In order to obtain a larger electrostatic capacity while maintaining predetermined dimensions, therefore, the number of stacked inner electrodes must be increased and the thickness of the dielectric layer must be reduced. However, when trying to satisfy those requirements, a problem arises in that structural defects, such as cracks and delamination, are more likely to occur during firing. In view of such problems, various ways to prevent the structural defects, such as cracks and delamination, during the firing by reducing thicknesses of ceramic green sheets and inner electrodes and stacking them in larger numbers, are proposed as described in Japanese Unexamined Patent Application Publication No. 2003-318060, for example.
However, the monolithic ceramic capacitor including ceramic layers, which are thinner and are stacked in a larger number, has a problem in that cracks are more likely to occur when thermal shocks is applied during, e.g., soldering.